Follicular growth and estradiol follow-up after subcutaneous xenografting of fresh and cryopreserved human ovarian tissue

Objective: To assess ovarian cortex surrounding benign ovarian cysts after cryopreservation and grafting to severe combined immunodeficient (SCID) mice. Design: Animal study. Setting: Academic research laboratories. Patient(s): Ovarian tissue obtained from 15 patients. Intervention(S): Grafting of fresh and frozen/thawed ovarian tissue into the subcutaneous space of 22 SCID mice for 80 days. Main Outcome Measure(s): Histologic analysis before and after grafting. Serum E-2 measured before (after 37 days of grafting) and after FSH/LH supplementation (end of the study). Result(s): After grafting, follicular density had decreased for frozen/thawed tissue in all cases. The follicular distribution was modified in fresh tissue: Primordial follicles proportion was reduced (79% vs. 17%), whereas the primary and secondary ones were increased (21% vs. 57% and 0% vs. 23%, respectively). The same tendency was observed in frozen/thawed tissue. Significant E-2 secretion was obtained before and after FSH/LH supplementation in castrated mice, grafted with either fresh or frozen/thawed tissue. Conclusion(s): Fresh and cryopreserved ovarian cortex surrounding benign ovarian cysts grafted into the subcutaneous space of SCID mice is able to sustain ovarian tissue function, although follicular growth appears lower with frozen/thawed tissue.